An introducer is used in the medical field to establish and provide access to the arterial system of a patient. Once established, the introducer provides a means of access to the arterial system for certain instruments or devices, and specifically, that device can be a guide wire that passes through the introducer wherein the distal end of the guide wire is located in the particular desired artery of the patient.
In a typical introduction of a guide wire into a patient, a needle is first inserted into the patient with its distal end positioned in the artery. A guide wire is then normally slid through the needle such that the distal end of the guide wire is located within that particular artery. At that point, the needle is removed while the guide wire remains in its position in the artery. An introducer, with a dilator, is then inserted over the guide wire into the artery. The dilator is then removed while the introducer is retained in that position with the guide wire passing therethrough such that other medical devices can be threaded over and along the guide wire through the introducer into the particular artery.
For example, a stent can be introduced through the introducer and located at the desired location with a balloon that is inflated to emplace the stent and the balloon removed.
In any case, there must be a seal between the introducer and the particular device that passes through the introducer to be used in treating the patient. One of the chronic problems, however with such devices is that the sealing function of the introducer against the particular device is normally carried out by the use of a flexible or elastomeric material and, over time, that material becomes fatigued or distorted and eventually result in leaking through the introducer.
Further, the problem occurs when there is no device at all passing through the introducer, that is, when a device is removed by pulling it outwardly from the introducer, there is a tendency to distort the seal as that device is pulled through the seal and thus create a leakage situation. Basically, the pulling of a device outwardly away from the patient through the seal during the removal of that device causes the seal to pull outwardly and create a distortion of that seal.
It would, therefore, be desirable to have an arrangement that provides a good, improved seal within the introducer that would provide a seal between the introducer and any device that passes through the introducer and also lessen the problem of leaking seals.
It would be further advantageous to have a seal that does not experience the normal distortion that occurs when a device is pulled outwardly from the introducer so that the leaking resulting from that distortion is lessened.
It would be further advantageous to have a seal arrangement that is relatively inexpensive to implement and which fits readily within the normal housing of an introducer such that the assembly of an introducer is not made unduly difficult.